Method and apparatus for sealing leaks

ABSTRACT

Leaks can be sealed quickly by methods employing a flexible patch applied by a resilient applicator that can be caused to exert suffieient force against the patch and the leaking surface to stop fluid flow while a leak sealant is curing.

This application is a division of application Ser. No. 08/158,695, filedDec. 2, 1993, now U.S. Pat. No. 5,423,932.

BACKGROUND OF THE INVENTION

This invention relates to the sealing of leaks, and more particularly toa leak sealing patch and a hand tool for applying such a patch to afluid containing body and to methods using such a tool and patch. Priorleak sealing tools and methods, as exemplified by U.S. Pat. No.3,645,816, required that the surface area surrounding a leak bethoroughly cleaned before a patch could be applied, and also that anyfluid pressure within the leaking body be eliminated by draining fluidfrom the body. Also, the tools used to apply leak seal patches were madefrom rigid materials that could not be deformed to coilform to the shapeof the surface area around the leak. This made it necessary to have aplurality of tools for applying patches with each tool having a shapeconforming to a single specific area or contour.

OBJECTIVES OF THE INVENTION

Accordingly, it is an object of this invention to provide improvedapplicators, patches and methods for sealing leaks.

Another object is to seal leaks in fluid containing bodies withoutrequiring that such bodies be drained or that their internal fluidpressure be eliminated.

A further object is to seal leaks in the outer surface of bodies thatare immersed in liquid.

A still further object is to facilitate the use of a single applicatorfor sealing leaks in different types of bodies having different sizesand shapes.

Another object is to provide a patch that can be used to seal leaks inbodies of differing shapes and sizes.

An additional object is to provide an applicator for a leak sealingpatch that can be used on non-flat, non-horizontal surfaces withoutpermitting the patch to fall out of the applicator.

Still another object is to provide a quick curing leak sealing patchthat can be used to seal pressurized and submerged leaks.

A further object is to provide methods for quickly sealing leaks underwidely varying conditions in bodies of differing shapes.

A still further object is to provide relatively simple, economical anddurable leak sealing tools and patches, and methods of using such toolsand patches that can be employed by persons that do not have specialtraining or skills and which do not possess defects found in similarprior art devices and methods.

Other objects and advantages of the invention will be found in thespecification and claims and the scope of this invention will be setforth in the claims.

DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of an embodiment of the invention.

FIG. 2 is a cross sectional view taken along the line 2--2 in FIG. 1.

FIG. 3 is a partial side view of the application of this inventiondeformed against a curved body.

FIG. 4 is a cross sectional view taken along the line 4--4 in FIG. 3.

FIG. 5 is an end view of the applicator shown in FIG. 1 with the patchremoved.

FIG. 6 is a plan view of a patch in accord with this invention with thesealant omitted.

FIG. 7 is a partial cross sectional side view showing another embodimentof the invention.

DESCRIPTION OF THE INVENTION

The drawing illustrates methods, tools and patches in accord with thisinvention for sealing leaks 1 in a fluid containing body such as acylindrical pipe 2. A hand tool in the form of an applicator 3 is usedto secure a leak sealing patch 5 to the outside surface of pipe 2 in thearea surrounding the leak.

Applicator 3 comprises a generally circular, hollow, resilient,deformable unitary member 6 having a cup-shaped wall portion 7 thatdefines a circular cavity 8 at one of its ends 10. A peripheral rim orflange 11 extends inwardly toward the center of the applicator so as tosurround and overlie cavity 8. Flange 11 defines the circular terminalouter surface 12 of member 6. Wall 7 has at its center within cavity 8 acircular protrusion that defines a hollow blister 13 that extends towardouter surface 12. Blister 13 is perforated by a circular center hole 14.A generally circular hollow tubular portion 15 extends from wall 7 inthe direction opposite to surface 12 and provides resilient deformablemember 6 with a hole 16 through its center. Tubular portion 15 may besurrounded by a pair of integral circumferential stabilizing ribs 17.The diameter D at end 10 of cup-shaped wall 7 may be in the range ofabout one to six inches, and the height H may be within a ratio of about1:1 to about 1:5 of the diameter D.

A circular peripheral rim 18 surrounds and extends outwardly away fromtubular portion 15 at the opposite end 19 of member 6. A threaded endcap 20 has a circular peripheral flange 21 which overlies and capturesrim 18 so as to connect the end cap to member 6. Applicator 3 includes arigid handle 23 which has a threaded end 24 that screws into end cap 20for connecting the handle to member 6. An integral rigid cylindricalplunger or rod portion 22 of reduced diameter extends from end 24 intotubular portion 15. A bushing 25 inserted into end 19 protects andsupports tubular portion 15 and helps hold member 6 and handle 23together.

Patch 5 includes a piece 26 of flexible fluid permeable fabric. Ideallythe area of piece 26 will be sufficient to cover leak 1 and surround thesurface of body 2 on all sides of the leak. However, when the leak isthe result of a large crack or other rupture, two or more overlappingpatches 5 may have to be applied. The center portion 27 of piece 26should be reinforced so that it is flexible but fluid-impervious andsufficiently strong to withstand enough applied force to stoppressurized fluid from flowing out of leak 1 while the seal is curing.Center portion 27 may comprise a reinforcing flexible sheet member 28having one side 29 secured to piece 26 by a bonding agent or by heatfusion. The center portion 27 can also be reinforced by impregnatingpiece 26 with rubber or plastic that will harden into a strong flexiblefluid impervious mass. As shown in FIGS. 2 and 4 sealant 30substantially covers and adheres to piece 26 and the opposite side 31 ofsheet member 28.

Piece 26 may be made from any strong flexible fabric comprisinginterconnected strands, such as woven and non-woven cloth, tape andmesh, and piece 26 may be made from natural, synthetic, metal or ceramicfibers. Preferably piece 26 is made from extremely high tensil strengthKevlar or Aramid aromatic polyamid fibers. Sheet member 28 may be madefrom flexible fluid-impervious material that is easily bondable orfusible to the material of piece 26. Hard natural rubber or syntheticrubbers such as styrene-butadiene-styrene may be used for sheet member28, but preferably member 28 should be made from Neoprene rubber. Thesealant 30 should cure rapidly between temperatures of about 5 to 25degrees C. without the addition of external heat and should securelybond to piece 26 and sheet member 28. Preferably, sealant 30 is an epoxyresin that cures in about one minute without external heat. Examples, ofsuitable sealants are disclosed in U.S. Pat. Nos. 4,569,956; 4,565,837and 4,396,754. Also, usable are the slightly slower curing materialsdisclosed in U.S. Pat. Nos. 3,976,613; 3,922,358 and 3,556,831.Resilient deformable member 6 should be made from a material to whichsealant 30 does not adhere, and preferably is made from silicone rubber.

FIG. 7 shows another embodiment that is identical to that of FIGS. 1-6,except that pressure release means 35 has been placed inside ofcup-shaped wall 7. A small hole 36 through wall 7 is covered by aflexible flap valve 37 that will close the hole. When pressure withinthe applicator 3 needs to be released, a small rod or wire can beinserted through hole 36 and flap 37 can be pushed away from the hole torelease the pressure.

This invention also includes methods of sealing leaks which will beapparent from the operation of applicator 3. Piece 26 is cut to a sizethat will enable the entire patch 5 to fit within cup-shaped member 7,and sheet member 28 is fused or bonded to the central area of piece 26.The patch is placed inside of cup-shaped member 7 and a generous amountof sealant 30 is spread over the entire area member 28 and overessentially the entire area of piece 26. Sealant 30 should permeate thefibers and/or the spaces between the fibers or strands of piece 26.Patch 5 is surrounded by resilient deformable member 7 and one side 32of the patch is supported within the applicator and its opposite side 33is exposed through the outer surface 12 at the applicator's open end 10.By overlapping patch 5 with flange 11, patch 5 is prevented fromescaping from the applicator when open end 10 must be tilted sideways ordownwardly. Outer surface 12 is placed against the surface of body 2surrounding and adjacent leak 1. Force is applied at the opposite end ofmember 6 through handle 23 so as to deform flange 11 and placeessentially the entire outer surface 12 into contact with the surface ofbody 2. Sufficient additional force is applied by handle 23 to deformwall 7 and blister 13 against side 32 of the patch and force side 33 ofthe patch into contact with the area of body 2 surrounding the leak. Theeffect of blister 13 and wall 7 deforming and pressing against piece 26is to generally mold or shape piece 26 and sheet member 28 to thecontour of the surface of body 2. Applying additional force to handle 23will compress tubular portion 15 and cause rod portion 22 to movethrough holes 14 and 16 into contact with side 32 opposite the centralpart of sheet member 28. Sufficient pressure should now be applied tosheet member 28 and piece 26 by pressing on rod portion 22 to stop fluidfrom escaping through leak 1. A relatively thin layer of sealant 30 willbe trapped between sheet member 28 and body 2, and piece 26 will holdadditional sealant 30 in contact with the surface of body 2 around theleak. The pressure from cup 7 and rod portion 22 should be maintainedagainst patch 5 until the sealant 30 has cured and the leak has beensealed. The force is then removed from the handle end of applicator 3and the applicator is pulled away from body 2 and patch 5. Theapplicator will return to its original shape, but patch 5 will continueto conform to the shape of body 2 in the area around leak 1. The fabricfrom which piece 26 is made acts as the medium for holding and shapingsealant 30 before and during the curing process and as reinforcement forstrengthening the sealant after it has cured. Additional sealant 30 nowmay be spread over and around patch 5 to reinforce the seal.

It has thus been shown that by the practice of this invention only oneflexible deformable applicator 3 is required for sealing leaks invarious types of vessels, tanks, pipes and containers of many differentsizes and shapes. Applicator 3 can be used to apply patches 5 onoverhead surfaces and on horizontal and vertical surfaces withoutpermitting escape of the patch; flange 11 overlaps patch 5 and holds thepatch inside of cup shaped wall 7 when the handle 23 is pointedhorizontally or downwardly. Great force can be applied by plunger 22 tohold sheet member 28 tightly against the surface of the body beingrepaired so fluid does not have to be drained from the body nor doesinternal fluid pressure have to be relieved. Flange 11 also preventspatch 5 from being pushed away or sliding away from the applicator orthe area around the leak when plunger 22 applies a large force againstthe patch. Reinforcing ribs 17 prevent lateral collapse of tubularmember 15 when force is applied by the plunger. The surface around theleak does not have to be totally clean and the applicator 3 can applypatches 5 to bodies submerged in water, hydrocarbons or oil, as forexample when repairing ship hulls or transformers. Pressurized leaks upto 90 psi have been sealed by this invention.

While the invention has been described with reference to particularembodiments, it is not intended to illustrate or describe herein all ofthe equivalent forms or ramifications thereof. Also, the words used arewords of description rather than limitation, and various changes may bemade without departing from the spirit or scope of the inventiondisclosed herein. It is intended that the appended claims cover all suchchanges as fall within the true spirit and scope of the invention.

What is claimed is:
 1. A patch for sealing a leak in a fluid containingbody having a fluid under pressure therein, said patch comprising apiece of fluid-permeable, flexible fabric having a flexible,fluid-impervious pressure resistant center portion, a quick-curingadhesive substantially covering and adhering to one side of said fabricand said center portion, said center portion being constructed andarranged to be held tightly against a surface of said body adjacent saidleak by force applied from an opposite side of said center portion, andsaid center portion being effective to stop pressurized fluid fromflowing out of said leak prior to the curing of said adhesive, wherebysaid patch is capable of sealing pressurized leaks.
 2. The patch definedin claim 1 wherein said center portion comprises a flexiblefluid-impervious sheet member affixed to one side of said piece.
 3. Thepatch defined in claim 2, wherein said piece comprises aromaticpolyamide fibers, said sheet member comprises neoprene rubber, and saidadhesive comprises quick curing epoxy resin.